[0002] The present invention relates to fasteners in general, and more particularly to a
fastener that may be tightened without using a key (or other tools).
[0003] Conventional tool chucks may have a turn ring that is rotatable using a chuck key
to extend and retract chuck jaws. Although such tool chucks are generally thought
to provide acceptable Performance, they are not without shortcomings. For example,
the conventional tool chuck requires cumbersome chuck key operations, chuck key retention,
and other inconveniences.
[0004] In view of the shortcomings associated with chuck keys, tool chucks have been developed
that have a turn ring (or sleeve) that is rotated manually, without using a chuck
key, to tighten the chuck jaws. However, it may be difficult to impart sufficient
clamping force using a keyless tool chuck.
[0006] EP 0 924 038 A2 discloses a bit attaching arrangement for a power tool, including a beveled pinion
gear.
[0007] According to a first aspect of the present invention, there is provided a fastener
comprising the features of claim 1.
[0008] According to a second aspect of the present invention, there is provided a method
comprising the steps of claim 13.
[0009] The above and other features of the invention including various and novel details
of construction and combinations of parts will now be more particularly described
with reference to the accompanying drawings. It will be understood that the details
of the example embodiments are shown by way of Illustration only and not as limitations
of the invention. The principles and features of this invention may be employed in
varied and numerous embodiments within the scope of the invention, as defined by the
appended claims.
[0010] The present invention will become more fully understood from the detailed description
below and the accompanying drawings, wherein like elements are represented by like
reference numerals, which are given by way of illustration only and thus are not limiting
of the present invention.
Figs. 1A and 1B are schematic illustrations of an example tool chuck with a nutating
gear reduction.
Fig. 2 is an exploded view of a front sleeve and a rear sleeve that may be implemented
in the tool chuck depicted in Figs. 1A and IB.
Fig. 3A is a schematic illustration of the nutating gear reduction system depicted
in Fig. IB.
Fig. 3B is a partial perspective view of a nutating gear and a nut that may be implemented
in the tool chuck depicted in Figs. 1A and IB.
Figs. 4A and 4C are schematic illustrations of another example tool chuck with a nutating
gear reduction.
Fig. 4B is a perspective view of a chuck jaw that may be implemented in the tool chucks
depicted in Figs. 4A and 4C.
Figs. 5A and 5B are schematic illustrations of another example tool chuck with a nutating
gear reduction.
Fig. 6 is a partial exploded view of the tool chuck depicted in Fig. 5A.
Fig. 7 is a schematic Illustration of another example tool chuck with a nutating gear
reduction
Fig. 8 is a schematic illustration of another example tool chuck with a nutating gear
reduction.
Figs. 9-13 are schematic illustrations of a fastener with a nutating gear reduction
in accordance with an example, non-limiting embodiment of the present invention.
[0011] Fig. 1A shows an example of a tool chuck 75 with a nutating gear reduction. The tool
chuck 75 may be provided on a power driver (e.g., a drill) for holding a tool (e.g.,
a drill bit). It will be appreciated, however, that the tool chuck 75 may be suitably
implemented on a variety of power drivers (other than drills) for holding a variety
of tools (other than drill bits).
[0012] With reference to Fig. 1A, the tool chuck 75 may include a chuck body 20. The rear
end of the chuck body 20 may be mounted on a spindle 85 of a power driver 95. The
forward end of the chuck body 20 may have passageways that slidably support a plurality
of chuck jaws 2. The chuck jaws 2 may be inclined so that respective forward ends
of the chuck jaws converge toward an axis 50 of the chuck body 20. The chuck jaws
2 may have respective radially outward facing threads 3. For clarity of illustration,
only a single chuck jaw 2 is depicted in Fig. 1.
[0013] In this example, the chuck jaws 2 may be characterized as "threaded" chuck jaws.
That is, the chuck jaws 2 may be actuated (i.e., advanced and/or retracted) via the
radially outward facing threads 3 interacting with radially inward facing threads
18 of a nut 16. However, the present example tool chuck is not limited in this regard.
For example, the nutating gear reduction may be suitably implemented using "pusher"
jaws, as will be discussed below with respect to other examples.
[0014] The chuck body 20 may rotatably support a rear sleeve 4 and a front sleeve 6. Turning
briefly to Fig. 2, the rear sleeve 4 and the front sleeve 6 may be provided as two
separate and distinct elements to facilitate assembly of the tool chuck 75. It will
be appreciated, however, that the rear sleeve 4 and the front sleeve 6 may be formed
of a unitary, one-piece construction. The rear sleeve 4 and the front sleeve 6 may
be rotationally fixed together. In this way, the rear sleeve 4 and the front sleeve
6 may be rotated together relative to the chuck body 20. The front sleeve 6 may have
a rear face 7 that is inclined relative to the axis 50. The rear face 7 of the front
sleeve 6 may act on the front face of a nutating gear 10 through the bearing 8.
[0015] The nutating gear 10 may be arranged in the tool chuck 75 such that its axis is inclined
relative to the axis 50 of the chuck body 20. The chuck body 20 may extend through
an opening of the nutating gear 10. The rear face of the nutating gear 10 may include
a set of teeth 12 that interact with the nut 16, and a set of teeth 13a that interact
with a fixing gear 5.
[0016] The fixing gear 5 may be fixed to the chuck body 20. The chuck body 20 may extend
through an opening of the fixing gear 5. The front face of the fixing gear 5 may include
a set of teeth 13b that engage with the teeth 13a on the nutating gear 10. The number
of teeth 13b on the fixing gear 5 and the number of teeth 13a on the nutating gear
10 may be selected so that the nutating gear 10 and the fixing gear 5 (and thus the
chuck body 20) maintain the same relative rotational positions with respect to each
other. Thus, as the nutating gear 10 nutates, the two sets of teeth 13a, 13b may interact
so that the fixing gear 5 prevents the nutating gear 10 from rotating relative to
the chuck body 20 about the axis 50. For example, an equal number of teeth 13a, 13b
may be provided so that the fixing gear 5 prevents a rotational movement of the nutating
gear 10 relative to the chuck body 20 about the axis 50.
[0017] The example is not limited to a nutating gear 10 that is rotationally fixed to the
chuck body 20. For example, different numbers of teeth 13a, 13b may be provided so
that the nutating gear 10 rotates relative to the chuck body 20. Such relative rotation
(between the nutating gear 10 and the chuck body 20) may be controlled by varying
the difference in the number of teeth 13a, 13b. In this regard, the rotational movement
of the nutating gear 10 (relative to the chuck body 20) may be restrained by the interacting
teeth 13a, 13b.
[0018] It will be appreciated that the nutating gear 10 may be rotationally fixed to the
chuck body 20 by structure other than the fixing gear 5. For example, the chuck body
20 may include splines (not illustrated) that are received in radially inward facing
passages (not illustrated) provided in the nutating gear 10. Such passages may extend
along a longitudinal axis of the nutating gear 10. Thus, as the nutating gear 10 nutates,
the splines may pass back and forth through the passages and at the same time prevent
the nutating gear 10 from rotating relative to the chuck body 20. The cooperating
splines and inward facing passages will be described and illustrated with respect
to other examples.
[0019] A bearing 8 may be interposed between the front sleeve 6 and the nutating gear 10
to facilitate a relative rotational movement between the front sleeve 6 and the nutating
gear 10.
[0020] The nut 16 may be mounted for rotation about the chuck body 20. The nut 16 may be
of a unitary, one-piece construction or of a split nut variety, as is well known in
this art. The nut 16 may have radially interior threads 18 that engage the radially
outward facing threads 3 on the chuck jaws 2 for advancing and/or retracting the chuck
jaws 2. The chuck body 20 may extend through an opening of the nut 16. The nut 16
may have a front face that is provided with a set of teeth 14. The teeth 14 of the
nut 16 may engage with the teeth 12 of the nutating gear 10.
[0021] The nutating gear 10 may be inclined relative to the nut 16 so that the teeth 12
of nutating gear 10 may only touch the teeth 14 of the nut 16 at one contact area
25. Thus, the diameter and circumference of the nutating gear 10 may be larger than
that of the nut 16. Further, the corresponding sets of teeth 12, 14 may be of the
same pitch so that the larger nutating gear 10 may have more teeth 12 around its circumference
than does the smaller nut 16.
[0022] In the example depicted in Fig. 1A, the sets of teeth 12 and 13a are provided on
the same face of the nutating gear 10, and thus the fixing gear 5 and the nut 16 are
provided on the same side of the nutating gear 10. However, the example is not limited
in this regard. For example, as shown in Fig. 1B, the sets of teeth 12 and 13a may
be provided on opposite faces of the nutating gear 10. Here, the fixing gear 5 and
the nut 16 are provided on opposite sides of the nutating gear 10. In all other respect,
the tool chuck 75 depicted in Fig. 1B may be similar to the tool chuck 75 depicted
in Fig. 1A.
[0023] A gear ratio of the nutating gear reduction will be appreciated with reference to
Fig. 3A, which schematically depicts the fixing gear 5, the nutating gear 10, and
the nut 16 arranged as shown in Fig. IB. The gear ratio may be determined according
to the following formula:

where NI is the number of teeth 13a of the nutating gear 10, N2 is the number of teeth
13b of the fixing gear 5, N3 is the number of teeth 12 of the nutating gear 10, and
N4 is the number of teeth 14 of the nut 16.
[0024] Thus, a designer may appropriately alter the teeth numbers NI to N4 to obtain the
desired gear reduction.
[0025] For example, consider a scenario in which the number NI of teeth 13a of the nutating
gear is 24, the number N2 of teeth 13b of the fixing gear is 24, the number N3 of
teeth 12 of the nutating gear is 27, and the number N4 of teeth 14 of the nut is 25.
Here, the gear ratio would equal 24*25/(24*25 - 24*27) or -12.5. A gear ratio of -12.5
means that 12.5 turns of the rear sleeve 4 would cause the nut 16 to rotate through
1 complete revolution. The negative value of the gear ratio indicates that the rear
sleeve 4 and the nut 16 rotate in opposite directions. It will be appreciated that
the threads 3 of the chuck jaws 2 and the threads 18 of the nut 16 may be left-handed
threads or right-handed threads to achieve the desired chuck jaw actuation. For example,
the threads 3, 18 may be appropriately selected so that a clockwise rotation of the
rear sleeve 4 (as viewed from the front end of the tool chuck) causes the chuck jaws
2 to advance.
[0026] The interfacing teeth sets 13a, 13b (and 12, 14) may have the same pitch, and therefore
the designer may alter the diameters of the gears to alter ratios of the interfacing
teeth sets. That is, the diameters of the respective gears may be altered to achieve
a desired gear ratio. To this end, the designer may vary parameters inclusive of a
nutating angle a and gear teeth offsets osl and os2. The nutating angle et is defined
as the angle a between the axis 50 of the chuck body 20 and the axis 51 of the nutating
gear 10. As shown in Fig. 3A, the axes 50, 51 intersect at an apex "A." The gear teeth
offset osl is measured from the axis 50 to a point on the axis 51 passing through
a plane containing the set of teeth 13a of the nutating gear 10. The gear teeth offset
os2 is measured from the axis 50 to a point on the axis 51 passing through a plane
containing the set of teeth 12 of the nutating gear 10.
[0027] The tool chuck 75 may operate as follows. An operator may turn the rear sleeve 4
relative to the chuck body 20 causing the front sleeve 6 to rotate relative to the
chuck body 20. The slanted rear face 7 of the front sleeve 6 may act upon the front
face of the nutating gear 10 (via the bearing 8), which may remain rotationally fixed
relative to the chuck body 20 (via the fixing gear 5, for example), thereby causing
the nutating gear 10 to nutate about the chuck body 20. As the nutating gear 10 nutates,
the contact area 25 between the nutating gear 10 and the nut 16 rotates around the
axis 50.
[0028] As stated above, the nutating gear 10 may be rotationally fixed. Thus, during one
nutation of the nutating gear 10, the nut 16 may be driven to rotate by an angular
distance equivalent to the difference between the number N3 of teeth 12 of the nutating
gear 10 and the number N4 of teeth 14 of the nut 16. Thus, the nutating drive may
be considered as a reduction gear System.
[0029] The interaction between the nutating gear and the nut 16 will be appreciated with
reference to the schematic view of Fig. 3B. Fig. 3B shows the nutating gear 10 with
the teeth 12 (the teeth 13a, which interact with the fixing gear 5, are not illustrated
for clarity of illustration; the nut's radially inward facing threads are also left
out for clarity). Here, the nutating gear 10 includes a reference mark RI and the
nut 16 includes a reference mark R2. One rotation of the input sleeve 6 produces one
nutation of the nutating gear 10. As the nutating gear 10 nutates, the reference mark
RI may remain at the same rotational position relative to the chuck body 20. One nutation
of the nutating gear 10 may turn the nut 16 by only a fractional rotation. The fractional
rotation of the nut 16 relative to the chuck body 20 is illustrated as the reference
mark R2 moves to a position R2' (shown in phantom).
[0030] As the nut 16 is driven to rotate, it may in turn drive the chuck jaws 2 opened or
closed (depending on the rotation direction) by virtue of the interaction between
the radially inward facing threads 18 and the radially outward facing threads 3.
[0031] As compared to conventional tool chucks, the nutating drive described above may achieve
a greater mechanical advantage for tightening the nut 16, which drives the jaws 2
into contact with a tool, such as a drill bit (for example).
[0032] As stated above, it will be appreciated that the difference in the numbers N3, NI
of teeth 12, 13a (respectively) provided on the nutating gear 10, the number N2 of
teeth 13b provided on the fixing gear 5, and the number N4 of teeth 14 provided on
the nut 16 may be varied to alter the final output drive ratio of driven nut 16.
[0033] Fig. 4A shows another example of a tool chuck 175 with a nutating gear reduction.
This example is similar to the previous example to the extent that it includes a nutating
gear reduction. However, there are several notable differences as described below.
[0034] With reference to Fig. 4A, the tool chuck 175 may include a chuck body 120 defining
an axis 150. As in the previous example, the rear end of the chuck body 120 may be
mounted on a spindle of a power driver.
[0035] In this example, the chuck jaws 102 are "pusher" chuck jaws 102, as opposed to the
threaded chuck jaws described with respect to the previous example. In this regard,
the chuck jaws 102 may be advanced and/retracted relative to the chuck body 120 by
a screw 115.
[0036] The chuck body 120 may extend through and support the screw 115 so that the chuck
body 120 and the screw 115 may be rotationally fixed together and the screw 115 may
be axially moveable relative to the chuck body 120 in the direction of the axis 150.
The chuck body 120 may include a spline 117 that may be received in a corresponding
feature provided on the screw 115. The spline 117 may guide the axial movement of
the screw 115, and at the same time prevent a relative rotation between the chuck
body 120 and the screw 115. It will be appreciated that the spline may instead be
provided on the screw 115, and such spline may be received by a corresponding feature
provided on the chuck body 120.
[0037] The rear end of the screw 115 may include radially outward facing threads 103 that
interact with radially inward facing threads 118 of a nut 116. The interaction of
the threads 103, 118 may influence the screw to advance and/or retract along the axis
150 of the chuck body 120. The forward end of the screw 115 may include radially oriented
passageways in which the chuck jaws 102 are respectively supported. The radially oriented
passageways may guide a radial movement of the chuck jaws 102, and at the same time
may rotationally fix the chuck jaws 102 to the screw 115.
[0038] The chuck body 120 may support a two-part sleeve inclusive of a front sleeve 106
and a rear sleeve 104. The front sleeve 106 may include passageways through which
the chuck jaws 102 are respectively slidable. The passageways of the front sleeve
106 may be inclined relative to the axis 150 of the chuck body 120. In this way, when
the chuck jaws 102 are advanced (via the screw 115), the passageways of the front
sleeve 106 may influence the chuck jaws 102 in a radial inward direction through the
radially oriented passageways of the screw 115 and toward the axis 150. And when the
chuck jaws 102 are retracted (via the screw 115), the passageways of the front sleeve
106 may influence the chuck jaws in a radial outward direction through the radially
oriented passageways of the screw 115 and away from the axis 150. The passageways
in the front sleeve 106 may rotationally fix the front sleeve 106 to the chuck jaws
102. Thus, the front sleeve 106, the chuck jaws 102, the chuck body 120, and the screw
115 may be rotationally fixed together.
[0039] Turning briefly to Fig. 4B, an example pusher chuck jaw 102 is schematically illustrated.
As shown, the chuck jaw 102 may have a tapered shape with a contact surface 102a.
The chuck jaw 102 may have several features that cooperate with the various passageways
provided in the tool chuck 175. For example, a first flange 102b may be provided to
cooperate with the corresponding radially oriented passageway of the screw 115. And
a second flange 102c may be provided to cooperate with the corresponding inclined
passageway of the front sleeve 106. The chuck jaw flanges and the corresponding passageways
may have complementary shapes. It will be readily apparent to those skilled in the
art that the pusher chuck jaws 102 may have numerous and alternative features that
cooperate with corresponding features of the tool chuck 175 to achieve the desired
advancing and retracting movements of the chuck jaws 102.
[0040] Turning back to Fig. 4A, the rear sleeve 104 may be mounted for rotation on the chuck
body 120 via a bearing 132. Thus, the rear sleeve 104 may be rotatable relative to
the front sleeve 106. To facilitate this relative rotation, a bearing 130 may be interposed
between the rear sleeve 104 and the front sleeve 106. The rear sleeve 104 may house
a nutating gear 110 and the nut 116.
[0041] The nutating gear 110 may be mounted for rotation on the rear sleeve 104 such that
its axis is inclined relative to the axis 150 of the chuck body 120. The chuck body
120 may extend through an opening of the nutating gear 110, The front face of the
nutating gear 110 may include a set of teeth 112 that interact with the nut 116 and
a set of teeth 113a that interact with a fixing gear 105.
[0042] The fixing gear 105 may be fixed to the chuck body 120. The chuck body 120 may extend
through an opening of the fixing gear 105. It will be appreciated that the chuck body
120 and the fixing gear 105 may be of a unitary, one-piece construction. The rear
face of the fixing gear 105 may include a set of teeth 113b that engage with the teeth
113a on the nutating gear 110. The number N2 of teeth 113b on the fixing gear 105
and the number NI of teeth 113a on the nutating gear 110 may be selected so that the
nutating gear 110 and the fixing gear 105 (and thus the chuck body 120) maintain the
same relative rotational positions with respect to each other. Thus, as the nutating
gear 110 nutates, the two sets of teeth 113a, 113b may interact so that the fixing
gear 105 prevents the nutating gear 110 from rotating relative to the chuck body 120
about the axis 150. For example, the same numbers NI, N2 of teeth 113a, 113b (respectively)
may be provided so that the fixing gear 105 prevents a rotational movement of the
nutating gear 110 relative to the chuck body 120 about the axis 150.
[0043] As in the previous example, this example is not limited to a nutating gear 110 that
is rotationally fixed to the chuck body 120. For example, different numbers NI, N2
of teeth 113a, 113b (respectively) may be provided so that the nutating gear 110 rotates
relative to the chuck body 120. Such relative rotation (between the nutating gear
110 and the chuck body 120) may be controlled by varying the difference in the numbers
N1, N2 of teeth 113a, 113b (respectively). In this regard, the rotational movement
of the nutating gear 110 (relative to the chuck body 120) may be restrained by the
interacting teeth 113a, 113b.
[0044] As in the previous example, it will be appreciated that the nutating gear 110 may
be rotationally fixed to the chuck body 120 by structure other than the fixing gear
105.
[0045] A bearing 108 may be interposed between the rear sleeve 104 and the nutating gear
110 to facilitate a relative rotational movement between the rear sleeve 104 and the
nutating gear 110. The front face of the nutating gear 110 may be provided with a
set of teeth 112.
[0046] The nut 116 may be axially fixed to the rear sleeve 104 and rotatable relative to
the rear sleeve 104 via a bearing 131. The chuck body 120 may extend through an opening
of the nut 116. The forward end of the nut 116 may include the radially inward facing
threads 118 that interact with the radially outward facing threads 103 of the screw
115 for advancing and/or retracting the screw 115 (and thus the chuck jaws 102). The
rear end of the nut 116 may be provided with a set of teeth 114. The teeth 114 of
the nut 116 may engage with the teeth 112 of the nutating gear 110.
[0047] The nutating gear 110 may be inclined relative to the nut 116 so that the teeth 112
of nutating gear 110 may only touch the teeth 114 of the nut 116 at one contact area
125. Thus, the diameter and circumference of the nutating gear 110 may be larger than
that of the nut 116. Further, the corresponding sets of teeth 112, 114 may be of the
same pitch so that the larger nutating gear 110 may have more teeth 112 around its
circumference than does the smaller nut 116.
[0048] In the example depicted in Fig. 4A, the sets of teeth 112 and 113a are provided on
the same face of the nutating gear 110, and thus the fixing gear 105 and the nut 116
are provided on the same side of the nutating gear 110. However, the example is not
limited in this regard. For example, as shown in Fig. 4C, the sets of teeth 112 and
113a may be provided on opposite faces of the nutating gear 110. Here, the fixing
gear 105 and the nut 116 are provided on opposite sides of the nutating gear 110.
Also, the nut 116 may be axially fixed to the rear sleeve 104 and rotatable relative
to the rear sleeve 104 via two bearings 131. In alternative examples, another number
of bearings 131 may be suitably implemented. Finally, as shown in Fig. 4C, the forward
end of the chuck body 120 may include a blind hole 1. By way of example only, the
blind hole 1 may have a hexagonal shape. The blind hole 1 may receive the shank of
a tool. In other respects, the tool chuck 175 depicted in Fig. 4C may be similar to
the tool chuck 175 depicted in Fig. 4A.
[0049] The tool chuck 175 may operate as follows. An operator may turn the rear sleeve 104
relative to the chuck body 120, the screw 115, the chuck jaws 102, the front sleeve
106, and the nutating gear 110. The rotation of the rear sleeve 104 may cause the
nutating gear 110, which may remain rotationally fixed relative to the chuck body
120 (via the fixing gear 105, for example), to nutate about the chuck body 120. As
the nutating gear 110 nutates, the contact area 125 between the nutating gear 110
and the nut 116 rotates around the axis 150.
[0050] As stated above, the nutating gear 110 may be rotationally fixed. Thus, during one
nutation of the nutating gear 110, the nut 116 may be driven to rotate by an angular
distance equivalent to the difference between the number N3 of teeth 112 of the nutating
gear 110 and the number N4 of teeth 114 of the nut 116.
[0051] As the nut 116 is driven to rotate, it may drive the screw 115 to advance or retract
along the axis 150 (depending on the rotation direction) by virtue of the interaction
between the radially inward facing threads 118 and the radially outward facing threads
103. In this example, the advancing and retracting movements of the screw 115 may
occur without any relative rotation between the screw 115 and the chuck body 120 (which
remain rotationally fixed together via the spline 117, for example). The translational
movement of the screw 115 may push or pull on the chuck jaws 102, thereby opening
and/or closing the same.
[0052] For example, during a closing Operation, the screw 115 (together with the chuck jaws
102) may be advanced along the axis 150. During this time, the inclined passageways
of the front sleeve 106 may influence the chuck jaws 102 in a radial inward direction
(i.e., toward the axis 150) through the radially oriented passageways of the screw
115.
[0053] As in the previous example, the difference in the numbers N3, NI of teeth 112, 113a
(respectively) provided on the nutating gear 110, the number N2 of teeth 113b provided
on the fixing gear 105, and the number N4 of teeth 114 provided on the nut 116 may
be varied to alter the final output drive ratio of driven nut 116.
[0054] Figs. 5A - 6 show another example of a tool chuck 275 with a nutating gear reduction.
This example is similar to the previous examples to the extent that it includes a
nutating gear reduction. Also, as in the example discussed above in section II, this
example may implement "pusher" chuck jaws 202. However, there are several notable
differences as described below.
[0055] With reference to Fig. 5A, the tool chuck 275 may include a chuck body 220 defining
an axis 250. As in the previous examples, the rear end of the chuck body 220 may be
mounted on a spindle 285 of a power driver 295.
[0056] An intermediate portion of the chuck body 220 may be provided with splines 217 that
interact with radially inward facing passages 21 of a nutating gear 210. In this example,
the splines 217 may have a spherical shape. However, it will be appreciated that splines
217 having numerous, alternative shapes may be suitably implemented. In this example,
four splines 217 may be uniformly spaced around the circumference of the chuck body
220. However, the example is not limited in this regard. For example, the number and
the spacing between the splines 217 may be varied.
[0057] The forward end of the chuck body 220 may include a nut 216. The nut 216 may be screw
coupled to a screw 215. To this end, the nut 216 may have radially interior threads
218 that engage radially outward facing threads 203 of the screw 215. The chuck body
220 (together with the nut 216) may be rotatable relative to the screw 215. During
this relative rotation, the interaction of the threads 203, 218 may influence the
screw 215 to advance and/or retract along the axis 250 of the chuck body 220.
[0058] The forward end of the screw 215 may include radially oriented passageways 215a in
which the chuck jaws 202 are respectively supported. The radially oriented passageways
215a may guide a radial movement of the chuck jaws 202, and at the same time may rotationally
fix the chuck jaws 202 to the screw 215.
[0059] The chuck body 220 may support a two-part sleeve inclusive of a front sleeve 206
and a rear sleeve 204. The front sleeve 206 may be mounted for rotation on the chuck
body 220. The chuck body 220 may extend through an opening of the front sleeve 206.
The forward end of the front sleeve 206 may fixedly support a cone 209. In this example,
and with reference to Fig. 6, the front sleeve 206 and the cone 209 may be provided
as two separate elements to facilitate assembly of the tool chuck 275. It will be
appreciated, however, that the front sleeve 206 and the cone 209 may be formed of
a unitary, one-piece construction.
[0060] The cone 209 may include passageways 209a through which the chuck jaws 202 are respectively
slidable. The passageways 209a of the cone 209 may be inclined relative to the axis
250 of the chuck body 220. In this way, when the chuck jaws 202 are advanced (via
the screw 215), the passageways 209a of the cone 209 may influence the chuck jaws
202 in a radial inward direction through the radially oriented passageways 215a of
the screw 215 and toward the axis 250. And when the chuck jaws 202 are retracted (via
the screw 215), the passageways 209a of the cone 209 may influence the chuck jaws
202 in a radial outward direction through the radially oriented passageways 215a of
the screw 215 and away from the axis 250. The passageways 209a in the cone 209 may
rotationally fix the cone 209 to the chuck jaws 202. Thus, the chuck jaws 202, the
cone 209, the front sleeve 206, and the screw 215 may be rotationally fixed together.
[0061] The rear end of the front sleeve 206 may fixedly support an output gear 226. The
chuck body 220 may extend through an opening of the output gear 226. The rear face
of the output gear 226 may be provided with a set of teeth 214. In this example, and
with reference to Fig. 6, the front sleeve 206 and the output gear 226 may be provided
as two separate elements to facilitate assembly of the tool chuck 275, and to allow
for a convenient manner in which the output gear 226 may be removed and replaced by
a new or alternative output gear (e.g., an output gear having a different number of
teeth). It will be appreciated, however, that the front sleeve 206 and the output
gear 226 may be formed of a unitary, one-piece construction.
[0062] The rear sleeve 204 may be mounted for rotation on the chuck body 220. The chuck
body 220 may extend through an opening of the rear sleeve 204. The rear sleeve 204
may be rotatable relative to the front sleeve 206. The rear sleeve 204 may have a
front face 207 that is inclined relative to the axis 250 of the chuck body 220. The
front face 207 of the rear sleeve 204 may act upon the rear face of a nutating gear
210. As shown in Fig. 6, the rear sleeve 204 may be of a two-part construction to
facilitate assembly. The two parts 204a, 204b of the rear sleeve 204 may be assembled
together to support opposing sides of the nutating gear 210. It will be appreciated,
however, that the rear sleeve 204 may be of a unitary, one-piece construction.
[0063] The nutating gear 210 may be arranged in the tool chuck 275 such that its axis is
inclined relative to the axis 250 of the chuck body 220. The chuck body 220 may extend
through an opening of the nutating gear 210. The nutating gear 210 may be mounted
in such a way that it remains rotationally fixed relative to the chuck body 220. That
is, the nutating gear 210 may nutate without rotating relative to the chuck body 220
about the axis 250. To this end, the nutating gear 210 may include radially inward
facing features that may cooperate with the spherical splines 217 provided on the
chuck body 220. In this example, the radially inward facing features may be in the
form of passages 211 that respectively receive the spherical splines 217. The passages
211 may extend along a longitudinal axis of the nutating gear 210. Thus, as the nutating
gear 210 nutates, the spherical splines 217 may pass back and forth through the passages
211 and at the same time may prevent the nutating gear 210 from rotating relative
to the chuck body 220.
[0064] A bearing (not illustrated) may be interposed between the rear sleeve 204 and the
nutating gear 210 to facilitate a relative rotational movement between the rear sleeve
204 and the nutating gear 210. The front face of the nutating gear 210 may be provided
with a set of teeth 212. The teeth 212 of the nutating gear 210 may engage with the
teeth 214 of the output gear 226.
[0065] The nutating gear 210 may be inclined relative to the output gear 226 so that the
teeth 212 of nutating gear 210 may only touch the teeth 214 of the output gear 226
at one contact area 225. Thus, the diameter and circumference of the nutating gear
210 may be larger than that of the output gear 226. Further, the corresponding sets
of teeth 212, 214 may be of the same pitch so that the larger nutating gear 210 may
have more teeth 212 around its circumference than does the smaller output gear 226.
[0066] It will be appreciated that the nutating gear 210 may be rotationally fixed to the
chuck body 220 by structure other than the spherical splines 217. For example, and
briefly turning to Fig. 5B, a fixing gear 205 may be fixed to the chuck body 220.
The front face of the fixing gear 205 may include a set of teeth 213b that engage
with a set of teeth 213a provided on a rear face of the nutating gear 210. The number
N2 of teeth 213b on the fixing gear 205 and the number Nl of teeth 213a on the nutating
gear 210 may be selected so that the nutating gear 210 and the fixing gear 205 (and
thus the chuck body 220) maintain the same relative rotational positions with respect
to each other. Here, opposite faces of the nutating gear 210 have respective sets
of teeth 212 and 213a. Thus, the fixing gear 205 and the output gear 226 may be provided
on opposite sides of the nutating gear 210.
[0067] As shown in Fig. 5B, a bearing 221 may be provided between the chuck body 220 and
the front sleeve 206. To this end, the chuck body 220 and the front sleeve 206 may
be provided with cooperating grooves in which the bearing 221 is provided. The bearing
221 may axially fix together and facilitate a relative rotation between the chuck
body 220 and the front sleeve 206. In other respects, the tool chuck 275 depicted
in Fig. 5B may be similar to the tool chuck 275 depicted in Fig. 5A.
[0068] The tool chuck 275 may operate as follows. An operator may turn the rear sleeve 204
relative to the chuck body 220 and the nutating gear 210. The rotation of the rear
sleeve 204 may cause the nutating gear 210, which may remain rotationally fixed relative
to the chuck body 220 (via the spherical splines 217 shown in Fig. 5A and/or the fixing
gear 205 shown in Fig. 5B, for example), to nutate about the chuck body 220. As the
nutating gear 210 nutates, the contact area 225 between the nutating gear 210 and
the output gear 226 may move around the circumference of the chuck body 220.
[0069] As stated above, the nutating gear 210 may be rotationally fixed. Thus, during one
nutation of the nutating gear 210, the output gear 226 may be driven to rotate by
an angular distance equivalent to the difference between the number N3 of teeth 212
of the nutating gear 210 and the number N4 of teeth 214 of the output gear 226.
[0070] The driven output gear 226 may rotate together with the front sleeve 206 and the
cone 209. The cone 209 (via the passageways 209a) rotates together with the chuck
jaws 202. The chuck jaws 202 (seated in radial passageways 215a) may drive the screw
215 to rotate relative to the nut 216 of the chuck body 220. This relative rotation
may advance or retract the screw 215 along the axis 250 (depending on the rotation
direction) by virtue of the interaction between the radially inward facing threads
218 and the radially outward facing threads 203. As the screw 215 advances or retracts
relative to the chuck body 220, the screw 215 may push or pull on the chuck jaws 202,
thereby opening and/or closing the same.
[0071] For example, during a closing operation, the screw 215 (together with the chuck jaws
202) may be rotated relative to the chuck body 220 and advanced along the axis 250
of the chuck body 220. During this time, the chuck jaws 202 may advance through (and
be guided by) the inclined passageways 209a of the cone 209. The inclined passageways
of the cones 209 may influence the chuck jaws 202 in a radial inward direction (i.e.,
toward the axis 250) through the radially oriented passageways of the screw 215.
[0072] During actuation of the chuck jaws 202, the rear sleeve 204 and the front sleeve
206 may rotate relative to the chuck body 220. Further, the rear sleeve 204 and front
sleeve 206 may rotate relative to each other. Relative to the chuck body 220, the
rear sleeve 204 may rotate in a direction that is counter to the rotational direction
of the front sleeve 206.
[0073] As in the previous examples, the difference in the number N3 of teeth 212 provided
on the nutating gear 210 and the number N4 of teeth 214 provided on the output gear
226 may be varied to alter the final output drive ratio of the output gear 226.
[0074] Fig. 7 shows another example, non-limiting example of a tool chuck 275' with a nutating
gear reduction. This example is similar to the example discussed above in section
III. However, this example may additionally include a switch 240 for disabling the
nutating gear reduction mechanism, as described below.
[0075] With reference to Fig. 7, the tool chuck 275' may include a chuck body 220' defining
an axis 250'. The rear end of the chuck body 220' may be mounted on a spindle 285'
of a power driver 295'.
[0076] An intermediate portion of the chuck body 220' may be provided with splines 217'
that interact with radially inward facing passages of a nutating gear 210'.
[0077] The forward end of the chuck body 220' may include a nut 216'. The nut 216' may be
screw coupled to a screw 215'. The nut 216' may have radially interior threads that
engage radially outward facing threads of the screw 215'. The chuck body 220' (together
with the nut 216') may be rotatable relative to the screw 215' to advance and/or retract
the screw 215' along the axis 250' of the chuck body 220'.
[0078] The forward end of the screw 215 may include radially oriented passageways in which
the chuck jaws 202' are respectively supported. The radially oriented passageways
may guide a radial movement of the chuck jaws 202', and at the same time may rotationally
fix the chuck jaws 202' to the screw 215'.
[0079] The chuck body 220' may support a two-part sleeve .inclusive of a front sleeve 206'
and a rear sleeve 204'. The front sleeve 206' may be mounted for rotation on the chuck
body 220'. The forward end of the front sleeve 206' may fixedly support a cone 209'.
The cone 209' may include passageways 209a' through which the chuck jaws 202' are
respectively slidable. The passageways 209a' in the cone 209' may rotationally fix
the cone 209' to the chuck jaws 202'. Thus, the chuck jaws 202', the cone 209', the
front sleeve 206', and the screw 215' may be rotationally fixed together.
[0080] The front sleeve 206' may support an output gear 226'. Similar to the previous example,
the output gear 226' and the front sleeve 206' may be rotationally fixed together.
In contrast to the previous example, the output gear 226' may be axially moveable
(i.e., in the direction of the axis 250') relative to the front sleeve 206'. For example,
the front sleeve 206' and the output gear 226' may be coupled together via cooperating
splines that extend in a longitudinal direction. The cooperating splines may be respectively
provided on the radially inward facing surface of the front sleeve 206' and the radially
outward facing surface of the output gear 226'. Such spline couplings (and other alternative
couplings) are well known in this art. The output gear 226' (which may be rotationally
fixed to the front sleeve 206') may be rotatable relative to the chuck body 220' (and
thus the nut 216'). The rear face of the output gear 226 may be provided with a set
of teeth 214'.
[0081] The front sleeve 206' may support the switch 240. The switch 240 may be moveable
in the axial direction relative to the sleeve 206'. The front sleeve 206' may include
a slot 249 for guiding the longitudinal movement of the switch 240. The radially inward
end of the switch 240 may be fixedly connected to a shift ring 242. The shift ring
242 may be fixedly mounted on the output gear 226'. Thus, the switch 240, the shift
ring 242, and the output gear 226' may be moveable together along the axis 250' relative
to the front sleeve 206' and the chuck body 220' (and thus the nut 216').
[0082] The rear sleeve 204' may be mounted for rotation on the chuck body 220'. The rear
sleeve 204' may be rotatable relative to the front sleeve 206'. The rear sleeve 204'
may have a front face 207' that is inclined relative to the axis 250' of the chuck
body 220'. The front face 207' of the rear sleeve 204' may act upon the rear face
of a nutating gear 210'.
[0083] The nutating gear 210' may be arranged in the tool chuck 275' such that its axis
is inclined relative to the axis 250' of the chuck body 220'. The nutating gear 210'
may be mounted in such a way that it remains rotationally fixed relative to the chuck
body 220'. To this end, the nutating gear 210' may include radially inward facing
passages 211' that may respectively cooperate with the spherical splines 217'. As
the nutating gear 210' nutates, the spherical splines 217' may pass back and forth
through the passages 211' and at the same time may prevent the nutating gear 210'
from rotating relative to the chuck body 220'.
[0084] The front face of the nutating gear 210' may be provided with a set of teeth 212'.
The teeth 212' of the nutating gear 210' may engage with the teeth 214' of the output
gear 226'.
[0085] The tool chuck 275' may operate differently depending on the axial position of the
switch 240. On the one hand, when the switch 240 is in the axial rearward position,
the nutating gear reduction mechanism may be enabled so that a user may have a mechanical
advantage in tightening the chuck jaws 202'. On the other hand, when the switch 240
is in the axial forward position, the nutating gear reduction mechanism may be disabled
so that the user may tighten the chuck jaws 202' more rapidly and without the mechanical
advantage.
[0086] More specifically, the operator may push the switch 240 in an axially rearward direction
through the slot 249 of the front sleeve 206'. The rearward axial movement of the
switch 240 may impart a corresponding rearward axial movement of shift ring 242 and
the output gear 226' relative to the chuck body 220'. During this movement, the nut
216' may pass through an opening in the output gear 226'.
[0087] With the switch 240 in the axial rearward position, the teeth 214' of the output
gear 226' may be engaged with the teeth 212' of the nutating gear 210', thereby enabling
the nutating gear reduction mechanism. The operator may then turn the rear sleeve
204' to actuate the tool chuck 275' as described above in section III.
[0088] The operator may push the switch 240 in an axially forward direction through the
slot 249 of the front sleeve 206'. The forward axial movement of the switch 240 may
impart a corresponding forward axial movement of shift ring 242 and the output gear
226' relative to the chuck body 220'. During this movement, the nut 216' may pass
through an opening in the output gear 226'.
[0089] With the switch 240 in the axial forward position, the teeth 214' of the output gear
226' may be disengaged from the teeth 212' of the nutating gear 210', thereby disabling
the nutating gear reduction mechanism. The operator may then turn the front sleeve
206' (and thus the cone 209') relative to the chuck body 220'. The cone 209' may rotate
together with the chuck jaws 202' and the screw 215'. The relative rotation between
the screw 215' and the nut 216' may advance or retract the screw 215' along the axis
250' (depending on the rotation direction of the front sleeve 206'). As the screw
215' advances or retracts relative to the chuck body 220', the screw 215' may push
of pull on the chuck jaws 202', thereby closing or opening the same.
[0090] Fig. 8 shows another example of a tool chuck 375 with a nutating gear reduction.
This example is similar to the previous examples to the extent that it includes a
nutating gear reduction. Also, this example may implement "pusher" chuck jaws 302.
However, there are several notable differences as described below.
[0091] With reference to Fig. 8, the tool chuck 375 may include a chuck body 320. The rear
end of the chuck body 320 may be mounted on a spindle of a power driver 395.
[0092] An intermediate portion of the chuck body 320 may be provided with splines 317 that
interact with radially inward facing passages 311 of a nutating gear 310 so that the
chuck body 320 and the nutating gear 310 are rotationally fixed together. In this
example, the splines 317 may have a spherical shape. However, it will be appreciated
that splines 317 having numerous, alternative shapes may be suitably implemented.
In this example, four splines 317 may be uniformly spaced around the circumference
of the chuck body 320. However, the example is not limited in this regard. For example,
the number and the spacing between the splines 317 may be varied.
[0093] The forward end of the chuck body 320 may include a nut 316. The nut 316 may be screw
coupled to a screw 315. To this end, the nut 316 may have radially interior threads
318 that engage radially outward facing threads 303 of the screw 315. The chuck body
320 (together with the nut 316) may be rotatable relative to the screw 315. During
this relative rotation, the interaction of the threads 303, 318 may influence the
screw 315 to advance and/or retract along the axis 350 of the chuck body 320.
[0094] The forward end of the screw 315 may include radially oriented passageways 315a in
which the chuck jaws 302 are respectively supported. The radially oriented passageways
315a may guide a radial movement of the chuck jaws 302, and at the same time may rotationally
fix the chuck jaws 302 to the screw 315.
[0095] The chuck body 320 may support a nutating mechanism housing ("NMH") sleeve 360. The
NMH sleeve 360 may be rotatable relative to.the chuck body 320. Such relative rotation
may be facilitated by a bearing 362. The NMH sleeve 360 may have a front face 307
that is inclined relative to the axis 350 of the chuck body 320. The front face 307
of the NMH sleeve 360 may act upon the rear face of the nutating gear 310.
[0096] The NMH sleeve 360 may support a front sleeve 306 and a clutch and lock ("CL") sleeve
370. The front sleeve 306 may be rotatable relative to the NMH sleeve 360. This relative
rotation may be facilitated by a bearing 364. The front sleeve 306 may include passageways
through which the chuck jaws 302 are respectively slidable. The passageways of the
front sleeve 306 may be inclined relative to the axis 350 of the chuck body 320. In
this way, when the chuck jaws 302 are advanced (via the screw 315), the passageways
of the front sleeve 306 may influence the chuck jaws 302 in a radial inward direction
through the radially oriented passageways 315a of the screw 315 and toward the axis
350. And when the chuck jaws 302 are retracted (via the screw 315), the passageways
of the front sleeve 306 may influence the chuck jaws 302 in a radial outward direction
through the radially oriented passageways 315a of the screw 315 and away from the
axis 350. The passageways in the front sleeve 306 may rotationally fix the front sleeve
306 to the chuck jaws 302. Thus, the chuck jaws 302, the front sleeve 306, and the
screw 315 may be rotationally fixed together.
[0097] The rear end of the front sleeve 306 may fixedly support an output gear 326. The
chuck body 320 may extend through an opening of the output gear 326. The rear face
of the output gear 326 may be provided with a set of teeth 314.
[0098] The nutating gear 310 may be arranged in the tool chuck 375 such that its axis is
inclined relative to the axis 350 of the chuck body 320. The chuck body 320 may extend
through an opening of the nutating gear 310. The nutating gear 310 may be mounted
in such a way that it remains rotationally fixed relative to the chuck body 320. That
is, the nutating gear 310 may nutate without rotating relative to the chuck body 320
about the axis 350. To this end, the nutating gear 310 may include radially inward
facing features that may cooperate with the spherical splines 317 provided on the
chuck body 320. In this example, the radially inward facing features may be in the
form of passages 311 that respectively receive the spherical splines 317. The passages
311 may extend along a longitudinal axis of the nutating gear 310. Thus, as the nutating
gear 310 nutates, the spherical splines 317 may pass back and forth through the passages
311 and at the same time may prevent the nutating gear 310 from rotating relative
to the chuck body 320.
[0099] It will be appreciated that the nutating gear 310 may be rotationally fixed to the
chuck body 320 by structure other than the spherical splines 317.
[0100] A bearing (not illustrated) may be interposed between the NMH sleeve 360 and the
nutating gear 310 to facilitate a relative rotational movement between the NMH sleeve
360 and the nutating gear 310. The front face of the nutating gear 310 may be provided
with a set of teeth 312. The teeth 312 of the nutating gear 310 may engage with the
teeth 314 of the output gear 326.
[0101] The nutating gear 310 may be inclined relative to the output gear 326 so that the
teeth 312 of nutating gear 310 may only touch the teeth 314 of the output gear 326
at one contact area 325. Thus, the diameter and circumference of the nutating gear
310 may be larger than that of the output gear 326. Further, the corresponding sets
of teeth 312, 314 may be of the same pitch so that the larger nutating gear 310 may
have more teeth 312 around its circumference than does the smaller output gear 326.
[0102] The CL sleeve 370 may be mounted on the NMH sleeve 360 so that the CL sleeve 370
may be axially moveable relative to the NMH sleeve 360 and rotationally fixed to the
NMH sleeve 360. For example, the radially inward facing surface of the CL sleeve 360
may include longitudinal splines (not illustrated) that cooperate with corresponding
features provided on the radially outward facing surface of the NMH sleeve 360. Such
coupling features are well known in this art, and therefore a detailed discussion
of the same is omitted.
[0103] The CL sleeve 370 may be axial moveable relative to the NMH sleeve 360 between the
illustrated rearward position (or "chuck drive mode") and a forward position (or "chuck
lock mode"). As shown in Fig. 8, in the chuck drive mode, a rear face of the CL sleeve
370 may include features 372 that engage with corresponding features 374 provided
on the driver housing. The features 372, 374 may cooperate to rotationally fix the
CL sleeve 370 (and thus the NMH sleeve 360) to the driver housing. The features 372,
374 may be designed to have profiles so that they separate from each other when a
predetermined torque is applied between the CL sleeve 370 and the driver housing.
[0104] In the chuck lock mode, a front face of the CL sleeve 370 may include protrusions
376 that engage with corresponding recesses 378 provided on a rear face of the front
sleeve 306. The protrusions 376 and the recesses 378 may cooperate to rotationally
fix the CL sleeve 370 (and thus the NMH sleeve 360) to the front sleeve 306. Also,
another front face of the CL sleeve 370 may include protrusions 380 that engage with
corresponding recesses 382 provided on a rear face of the chuck body 320. The protrusions
380 and the recesses 382 may cooperate to rotationally fix the CL sleeve 370 (and
thus the NMH sleeve 360) to the chuck body 320. In the chuck lock mode, the CL sleeve
370, the NMH sleeve 360, the front sleeve 306, and the chuck body 320 may be rotationally
fixed together. The CL sleeve 370 may include a spring loaded detent mechanism 390
that cooperates with a recess 392 provided in the NMH sleeve 360 to provisionally
retain the CL sleeve 370 in the chuck lock mode.
[0105] The tool chuck 375 may operate differently depending on the axial position of the
CL sleeve 370.
[0106] An operator may push the CL sleeve 370 in an axial rearward direction, as illustrated
in Fig. 8, to operate the tool chuck 375 in the chuck drive mode. The chuck drive
mode may allow the operator to utilize the output of the driver 395 to actuate the
chuck jaws 302. This may speed the chuck jaw actuation process, as compared to the
manually operated tool chuck described with respect to the previous examples.
[0107] In the chuck drive mode depicted in Fig. 8, and as stated above, the cooperating
features 372, 374 may be engaged to rotationally fix together the CL sleeve 370 (and
thus the NMH sleeve 360) and the driver housing. Further, as shown, the protrusions
376 of the CL sleeve 370 may be disengaged from the recesses 378 of the front sleeve
306, and the protrusions 380 of the CL sleeve 370 may be disengaged from the recesses
382 of chuck body 320. Thus, the front sleeve 306 may be rotatable relative to the
CL sleeve 370, and the chuck body 320 may be rotatable relative to the CL sleeve 370.
[0108] The operator may then actuate the driver 395 to rotate the chuck body 320. The chuck
body 320, by virtue of the splines 317, may rotate together with the nutating gear
310 relative to the NMH sleeve 360 (which may be rotationally fixed to the CL sleeve
370 and the driver housing). By virtue of the relative rotation between the nutating
gear 310 and the NMH sleeve 360, the front surface 307 of the NMH sleeve 360 may cause
the nutating gear 310 to nutate about the chuck body 320. As the nutating gear 310
rotates relative to the NMH sleeve 360 and nutates about the chuck body 320, it may
rotationally drive the front sleeve 306 via the interaction between the teeth 312,
314.
[0109] During one revolution of the chuck body 320, the nutating gear 310 may drive the
output gear 326 (and thus the front sleeve 306) to rotate by one full revolution plus
an angular distance equivalent to the difference between the number N3 of teeth 312
of the nutating gear 310 and the number N4 of teeth 314 of the output gear 326. At
the same time, the nut 316 of the chuck body 320 may rotate through one full revolution.
In this way, a speed differential may be achieved between the rotationally driven
front sleeve 306 and the rotationally driven nut 316. And since the front sleeve 306
may rotate together with the chuck jaws 302, the chuck jaws 302 (seated in the radial
passageways 315a) may drive the screw 315 to rotate relative to the nut 316 of the
chuck body 320. This relative rotation may advance or retract the screw 315 along
the axis 350 (depending on the rotation direction of the chuck body 320) by virtue
of the interaction between the radially inward facing threads 318 and the radially
outward facing threads 303. As the screw 315 advances or retracts relative to the
chuck body 320, the screw 315 may push or pull on the chuck jaws 302, thereby opening
and/or closing the same.
[0110] As in the previous examples, the difference in the number N3 of teeth 312 provided
on the nutating gear 310 and the number N4 of teeth 314 provided on the output gear
326 may be varied to alter the final output drive ratio of the output gear 326.
[0111] The cooperating features 372, 374 may function to limit the torque between the CL
sleeve 370 and the driver housing. This torque limiting feature may take the operator
out of the process, thereby effectively preventing the tool chuck from over tightening.
[0112] Once a tool is clamped by the chuck jaws 302, the operator may push the CL sleeve
370 in an axial forward direction to operate the tool chuck 375 in the chuck lock
mode. The chuck lock mode may prevent the chuck jaws 302 from loosening. Such loosening
may occur, for example, when the tool clamped by the chuck jaws 302 is driven in a
reverse direction (for example, when backing out a screw). The rotational resistance
of the screw may influence the chuck jaws 302 (and therefore the screw 315) to rotate
relative to the nut 316. Such relative rotation may result in a reduction of the clamping
pressure exerted by the chuck jaws 302. In a worst case scenario, the chuck jaws 302
may be rotationally driven while slipping occurs between the chuck jaws 302 and the
tool.
[0113] In the chuck lock mode, the cooperating features 372, 374 may be disengaged so that
the CL sleeve 370 (and thus the NMH sleeve 360) may be rotatable relative to the driver
housing. Further, the protrusions 376 of the CL sleeve 370 may be engaged with the
recesses 378 of the front sleeve 306, and the protrusions 380 of the CL sleeve 370
may be engaged with the recesses 382 of chuck body 320. Thus, the CL sleeve 370, the
NMH sleeve 360, and the front sleeve 306 may be rotatable together with the chuck
body 320. When the operator actuates the driver 395, the entire tool chuck 375 may
rotate together as a Single unit. The detent mechanism 390 cooperating with the recess
392 may retain the CL sleeve in the axially forward position.
[0114] In the chuck lock mode, the CL sleeve 370 may prevent any relative rotation from
occurring between the front sleeve 306 (and thus the chuck jaws 302 and the screw
315) and the chuck body 320 (and thus the nut 316). In this way, the CL sleeve 370
may prevent the chuck jaws 302 from loosening.
[0115] It will be appreciated that the CL sleeve may be suitably implemented in other examples.
For example, with slight modifications that will become apparent in view of the present
disclosure, the CL sleeve may be incorporated into the examples discussed above in
sections III and IV. The incorporated CL sleeve may serve the same advantageous functions
described above.
[0116] The various examples include chuck bodies that may be separate and distinct elements
from the spindle of the driver. However, it will be readily apparent to those skilled
in the art that the spindle and the chuck body may be of a unitary, one-piece construction.
[0117] Figs. 9-11 illustrate a fastener implementing a nutating gear reduction feature that
may be somewhat similar to the ones described above.
[0118] With reference to Fig. 9, the fastener 475 may cooperate with a hub 485 of a saw
(not shown) so that a saw blade 495 may be mounted on the saw. For example, the fastener
475 may include an external thread 418 that is screw coupled to an internal thread
provided on the distal end of the hub 485. A washer 497 may be interposed between
the fastener 475 and the saw blade 495.
[0119] With reference to Fig. 10, the fastener 475 may include a housing 404. The housing
404 may be of a two-piece construction (as shown in Fig. 11) to facilitate assembly.
A sleeve 406 may be press fit on the housing 404. The exterior surface of the sleeve
406 and/or the housing 404 may be knurled.
[0120] The housing 404 may rotatably support a nutating gear 410 and an anchor flange 405.
To this end, the housing 404 may include a shoulder 420 cooperating with a circumferential
groove in the nutating gear 410, and a shoulder 425 cooperating with a circumferential
groove in the anchor flange 405. The anchor flange 405 may be rotatable relative to
the housing 404 about a main axis 450. A driven gear 416 may extend through respective
openings provided in the nutating gear 410 and the anchor flange 405.
[0121] The nutating gear 410 may be arranged in the housing 404 such that its axis is inclined
relative to the main axis 450. The nutating gear 410 may includes two sets of teeth:
one set of teeth 413a interacts with the anchor flange 405; and another set of teeth
412 interacts with the driven gear 416.
[0122] The anchor flange 405 may include a set of teeth 415 for interacting with the washer
497, and a set of teeth 413b that engage with the teeth 413a on the nutating gear
410. The number of teeth 413b on the anchor flange 405 and the number of teeth 413a
on the nutating gear 410 may be selected so that the anchor flange 405 and the nutating
gear 410 maintain the same relative rotational positions with respect to each other.
By way of example only, an equal number of the teeth 413a, 413b may be provided. In
alternative embodiments, different numbers of teeth 413a, 413b may be provided so
that the nutating gear 410 may rotate relative to the anchor flange 405. Such relative
rotation (between the nutating gear 410 and the anchor flange 405) may be controlled
by varying the difference in the number of teeth 413a, 413b.
[0123] The driven gear 416 may be rotatably supported by the housing 404. To this end, a
distal end of the driven gear 416 (to the right in Fig. 10) may extend into an aperture
in the housing 404. The driven gear 416 may also be rotatably supported by the anchor
flange 405. For example, as shown, a tapered bearing surface of the driven gear 416
may abut against a cooperating tapered bearing surface of the anchor flange 405.
[0124] The distal end of the driven gear 416 may include a feature for receiving a tool
that a user may optionally utilize to rotationally drive driven gear 416. In this
example embodiment, the feature may be a hex recess 417 adapted to receive a Standard
Allen wrench (not shown). Numerous and varied tool receiving features (other than
the hex recess 417), which are well known in this art, may be suitably implemented.
By way of example only, a user may rotationally drive the driven gear 416 if the nutating
gear reduction becomes inoperable. The driven gear 416 may also include a protruding
shaft (to the left in Fig. 10) having the external thread 418. As discussed above,
the external thread 418 may be screw coupled to an internal thread provided on the
distal end of the hub 485 (see Fig. 9). The driven gear 416 may have a set of teeth
414 that engage with the teeth 412 of the nutating gear 410.
[0125] The nutating gear 410 may be inclined relative to the driven gear 416 so that the
teeth 12 of the nutating gear 410 may only touch the teeth 414 of the driven gear
416 at one contact area 426. Thus, the diameter and circumference of the nutating
gear 410 may be larger than that of the driven gear 416. Further, the corresponding
sets of teeth 412, 414 may be of the same pitch so that the larger nutating gear 410
may have more teeth 412 around its circumference than does the smaller driven gear
416.
[0126] The fastener 475 may operate as follows. Consider a tightening Operation. Initially,
an operator may turn the sleeve 406 and/or housing 404 relative to the hub 485 (which
supports the saw blade 495 and the washer 497) to screw couple together the external
thread 418 of the fastener 475 and the internal thread of the hub 485. Here, the component
parts of the fastener 475 may rotate together as a unit (and relative to the hub 485)
due to the internal frictional drag within the fastener 475. The interaction between
the cooperating threads of the fastener 475 and the hub 485 may draw the driven gear
416 into the hub 485.
[0127] Eventually, the teeth 415 of the anchor flange 405 may contact and press against
the washer 497 so that the anchor flange 405 (and thus the nutating gear 410) may
become rotationally grounded to the washer 497 (and thus the hub 485). In this condition,
further rotation of the sleeve 406 and/or housing 404 causes the shoulders 420, 425
of the housing 404 to respectively slide through the circumferential grooves of the
nutating gear 410 and the anchor flange 405. The shoulder 420 (as it slides through
the circumferential groove of the nutating gear 410) may cause the nutating gear 410
to nutate about the driven gear 416. As the nutating gear 410 nutates, the contact
area 426 between the nutating gear 410 and the driven gear 416 may move around the
main axis 450.
[0128] As stated above, the nutating gear 410 may be rotationally fixed to the anchor flange
405. Thus, during one nutation of the nutating gear 410, the driven gear 416 may be
driven to rotate by an angular distance equivalent to the difference between the number
N3 of teeth 412 of the nutating gear 410 and the number N4 of teeth 414 of the driven
gear 416.
[0129] The relative rotation between the driven gear 416 and the hub 485 may tighten the
fastener 475 (by virtue of the interaction between the external thread 418 of the
driven gear 416 and the internal thread of the hub 485) to securely clamp the saw
blade 495 in position.
[0130] It will be readily apparent that a loosening operation may be achieved by turning
the sleeve 406 and/or housing 404 in a direction opposite to that of the tightening
operation.
[0131] As in the above examples, the difference in the number N3 of teeth 412 provided on
the nutating gear 410 and the number N4 of teeth 414 provided on the driven gear 416
may be varied to alter the final output drive ratio of the driven gear 416.
[0132] In the embodiment depicted in Figs. 9-11, the fastener 475 includes an external thread
418 that cooperates with an internal thread of the hub 485. In alternative embodiments,
the fastener 475 (specifically, the driven gear 416) may include an internal thread
that cooperates with an external thread of the hub.
[0133] In the embodiment depicted in Figs. 9-11, the sets of teeth 412 and 413a are provided
on the same face of the nutating gear 410, and thus the teeth 414 (of the driven gear
416) and the teeth 413b (of the anchor flange 405) are provided on the same side of
the nutating gear 410. However, the invention is not limited in this regard. For example,
as shown in Figs. 12 and 13, the sets of teeth 412 and 413a may be provided on opposite
faces of the nutating gear 410. Here, the teeth 414 (of the driven gear 416) and the
teeth 413b (of the anchor flange 405) are provided on opposite sides of the nutating
gear 410.
[0134] As shown in Fig. 13, the driven gear 416 may be of a two-piece construction to facilitate
assembly of the fastener 475. The two-piece construction may include a shaft portion
416a and a distal flange portion 416b. The distal flange portion 416b, which may be
fixedly mounted on the shaft portion 416a, may include the teeth 414 that engage with
the teeth 412 of the nutating gear 410
[0135] In other respects, the fastener 475 depicted in Figs. 12 and 13 may be structurally
and functionally similar to the fastener 475 depicted in Figs. 9-11.
[0136] The example fastener may have numerous and varied applications that involve securing
parts together (other than securing a saw blade to the hub of a saw). The example
fastener may be suitable for application where the parts are to be secured together
temporarily and without requiring the use of tools (such as keys, wrenches and/or
screwdrivers, for example). By way of example only, the fastener may be implemented
to secure together component parts of framework (such as scaffolding, staging, etc.),
recreational equipment (such as the wheel and frame of a bicycle) and lawn and garden
equipment (such as lawn mowers, chain saws, etc.).
[0137] In alternative embodiments, the concepts discussed above may be implemented in an
instrument to provide a fine adjustment feature. By way of example only, such Instruments
may include telescopes, video cameras, lathes and/or drill presses. Here, the anchor
flange 405 may be fixed to the instrument housing (or some other supporting structure).
When a user rotates the housing 404, the nutating gear 410 will nutate and rotationally
drive the driven gear 416. By virtue of the nutating gear reduction feature, one rotation
of the housing 404 would cause only a fractional rotation of the driven gear 416,
which may be operatively connected to various gears, optics or other component parts
of the instrument.